This invention relates to a device for self-acting limitation of the ascending speed of divers.
On ascending, air exposed to increased pressure within the alveoli of a diver cannot exit fast enough because of the large change of volume, with decreasing pressure, particularly in the range of -2 and -3 bar. When a part of the alveoli bursts, air enters the bloodstream in an undissolved state and through the left part of the heart, to the body, thus reaching the brain which might lead to an embolism of the brain.
At low over pressures in the lungs, the over extension of the alveoli may lead to disturbances of blood circulation and attacks of vertigo. Once a diver experiences an emergency, he must try, on the one hand, to ascend as fast as possible, but he must also also try, on the other hand, not to surpass a maximum ascending speed, depending on the actual depth, in order to prevent the aforementioned damages to his lungs. The rule of thumb, for instance, is to observe the speed of rise of small air bubbles which depends on the water pressure and thus the actual depth.
Various devices are already known which are utilized to aid a diver while ascending from deep water. Such a known device shows the diver whether a constantly predetermined speed of rise is being maintained, where the minimum rise speed, due to the depth-dependence of the maximum speed of rise, cannot be obtained as needed in an emergency. Another known, extremely expensive electronic device signals to the diver when a certain defined maximum speed of rise is surpassed. Such a signal is practically worthless when the diver is under the influence of an emergency and thereby not capable of regulating the rising process according to the signal, an actuality when the diver has lost consciousness.
Based on the above, the present invention has an objective to provide a device made simply and at a low cost, working under difficult conditions and remaining reliable, which under all circumstances, thus also in the case of extraordinary conditions, assures that the diver does not rise at too great a speed and thus be exposed to life-threatening or injurious conditions.
This objective is obtained by a device which is characterized by a chamber connected to the interior space of the diving suit, with a sealing separating partition that divides such chamber and is elastically and longitudinally movable. This separating partition is connected to a valve closure part leading outwardly and capable of being sealingly movable. An ancillary valve seat is disposed in the outer envelope of the diving suit while the chamber sections, created by the separating partition, are connected to each other by a metering valve and a check valve opening in the direction of the closed chamber section. When a diver dives down, the opened check valve and the metering valve create pressure compensation between the air pressure in the diving suit and its immediately connected chamber section, on the one hand, and the other chamber section on the other hand, through the check valve and the metering valve. Even when rising slowly, pressure compensation occurs between both chamber sections by aid of the metering valve. When rising too fast and uncontrolled, however, the air influx through the metering valve does not suffice to create pressure compensation. Due to the fact that air pressure within the diving suit and within the chamber section immediately connected to it decreases while rising due to decreasing water pressure and the expansion of the diving suit caused by it, reduced pressure arises relative to the closed chamber section.
The result of this under pressure is that the elastic separating partition is pressed downwardly and together with it the connected valve closure part, which is thereby lifted off the valve seat in the diving suit's outer mantle, so that air egresses outwardly from the diving suit through the valve opening, thereby automatically reducing the speed of rise until such a value of the speed of rise is obtained where pressure compensation may occur through the metering valve between the chamber segments so that the separating partition with the valve closure part returns again elastically to its starting position where the valve opening the diving suit is closed.
This automatic regulation ensures that the diver does not rise improperly, even when he is in a panic or when he is prevented by intensive vertigo or unconsciousness to consciously and intelligently control his rising process.
A preferred embodiment of the invention provides that the separating partition is formed as a spring-biased piston. According to the invention, such a piston is sealingly guided along the side wall of the chamber and is pressed by a spring into its starting position.
An advantageous development may provide that the check valve and the metering valve are arranged in the piston. That means that the piston has openings which accept the valve and the check valve, thereby obtaining a particularly simple construction.
According to another embodiment of the invention, the separating partition is formed by a flexible membrane and the valve closure part is fastened to the central area of the flexible membrane. The outer rim of the membrane is tightly and solidly connected to the wall of the chamber and the valve closure part is fastened to the membrane where maximum movement of the membrane occurs due to its elasticity when the membrane is under pressure. Re-adjustment of the membrane occurs without any problem due to the characteristic elasticity of the membrane. The two chamber segments formed by the membrane are connected by two conduits extending outwardly around the membrane area. One conduit includes the check valve and the other includes the metering valve.
It is particularly advantageous to provide the metering valve of the afore-described arrangement with a device for the regulation of the throughput. The metering valve, when manufactured, is so dimensioned that it allows at normal or permitted rising and diving speeds a sufficient pressure compensation between both chamber segments. Adjustment of the throughput of the metering valve is very advantageous in order to make the device of the invention subsequently adjustable in order to conform to momentary demands.
The possibilities of use of the device according to the invention are finally increased by coupling the movable separating partition with an indicating device. Thereby the diver can read on the indicating device whether his rising speed is in a critical area, in such cases when he is capable of consciously regulating the change of depth.
A particularly fatigue-resistant embodiment consists of a device which contains a first chamber, at least partly separated from the surrounding water by an elastic partition, and a second chamber with an enclosing, tight separating partition which is elastically and longitudinally movable, such separating partition being operably connected to a valve closure part whose ancillary valve seat is arranged in the outer mantle of the diving suit, while the first and the second chambers are connected by a metering valve.
The function of the elastic wall of the diving suit is taken over in this embodiment by the elastic partition of the first chamber which is capable of deformation by the pressure of the surrounding water and may be deformed by the influence of it, thereby leading to a change of pressure in the first chamber which, when occurring slowly, compensates or offsets the pressure in the second chamber through the metering valve. When the change of pressure in the first chamber occurs too fast, the throughput of the metering valve, which is adjusted to a predetermined maximum rising speed, does not suffice to effect pressure compensation in the second chamber through the metering valve. The amount of air contained in the second chamber presses therefore upon the separating partition which is longitudinally movable in one direction. It may be, for instance a membrane which is connected to the valve closure part. This causes opening of the diving suit valve and thus to a diminution of the speed of rise until the whole arrangement is again in pressure equilibrium.
In an additional embodiment of the invention, a particular advantage may be achieved by arranging the first and second chambers separate from each other and providing a connecting conduit between the chambers together with the metering valve. This makes it possible to obtain a very flat mode of construction.
The uses of the described device are not restricted to their use by divers but comprise diving equipment of all kinds, for example, submersible diving equipment for rescuing people from submarines or the like.
Additional characteristics, advantages and details of the invention will be seen from the following description of preferred embodiments as well as from the accompanying drawings.